Conventional therapeutic packs may be used to provide a therapeutic treatment to an area of a living body to be subject to a cold or heat treatment. For example, therapeutic packs may be used to treat sports related injuries, by providing a cooling or heating temperature to the injured area.
It is believed that U.S. Pat. No. 4,044,773, which is expressly incorporated herein by reference, refers to a cold therapeutic package, in which water is sealed within an interior of a thin polyurethane bladder. The water is then frozen, resulting in the formation of a thin layer of ice within the bladder. After being exposed to a deforming force, such as a rolling or striking force, the layer of ice is divided into a plurality of small ice particles. These small ice particles may move at least substantially freely relative to one another when the cold therapeutic package is applied to an area to be subjected to a cold treatment, thereby promoting easier application of the cold package to the area. However, the thick materials of conventional cold pack bags do not conform readily to the complex, reentrant curves of the human body, because the bags must prevent leakage of water or other cooling medium.